+/- means plus or minus the RSME shown. The units are m/s^2 = meters per seconds squared.
We will not use the RSME's directly calculations but they indicate the data points are
precise to the 1/1000's place--one reason I urged you to write them down. The usual convention
is rounding the RSME to one sig. fig--for example 0.004280 = 0.004 after rounding.

The sum of the data points is 58.811 which has 5 sig. figs. When you

divide by 6, an exact number (i.e. 6 = 6.000.....), you get a 5 sig.

fig. number 9.801833333 = 9.8018 after rounding. The handout suggests a method
for getting the uncertainty or spread for small data sets: (max - min)/2 =
(9.819 - 9.784)/2 = 0.0175 = 0.02 after rounding. You would report result as
9.8018+/-0.02 = 9.80 +/- 0.02 after rounding. Many textbooks use the value of 9.80 m/s^2 for the accepted value of g as we will do in this lab. The acceleration of gravity depends on

this case we have (9.8018333 - 9.80)*100%/9.8 = 0 % since the difference between the two values is 0.0018333, suggesting a precision greater than that allowed by accepted value 9.80. Your percent error may not be zero. (See http://library.thinkquest.org/10796/ch1/ch1.htm ) Email me with questions. MORE DETAILS ARE PROVIDED BELOW ON THE LAB REPORT:

DETAILED REPORT GUIDELINES

Following is an explicit question-by-question outline of the work you

must show under each question in the correct order so I can grade it

easily. I want to grade without searching, sometimes in vain, for

indications you did work. This process should not be an Easter egg

hunt. If the report is disorganized with elements in the wrong place I

will not grade it or give you zero on portions I cannot find easily.

There are basically two types of questions, qualitative and

quantitative, applied to each question . In all cases, list the

questions as if the report was a homework assignment----with the

question number followed by the work you did and your answer. It's as

simple as that. You must include the data table as a separate element

with all your raw and derived numbers. But the derived numbers for the

data table must be shown explicitly under the appropriate analysis

question---just like a homework problem in which you show work.

You have two sections of the report: Preliminary Questions and Analysis

Questions.

Turn in the report in the following basic format. Under any question ,

do not say "See the data table ", without showing work. You must *show all the work* explicitly under the question leading to the number you entered in the table. Following the basic template below, I discuss how to answer each question. Please read this entire email message.

REPORT FORMAT :

Preliminary Questions

1. show work/reasoning

2. show work/reasoning

3. show work/reasoning

Analysis Questions

1. show work/reasoning

2. show work/reasoning

3. show work/reasoning

4. show work/reasoning

5. show work/reasoning

6. show work/reasoning

7. show work/reasoning

8. show work/reasoning

A COPY OF THE DATA TABLE MUST BE TURNED IN ON A SEPARATE SHEET; YOU CAN

PHOTOCOPY YOUR DATA TABLE PAGE FROM THE HAND OUT.

Following is what is required for each question:

Preliminary Questions:

1. Aside from the 0.5 cm lengths , as the FENCE moves through the gate what additional info do you need to find the sequence of average speeds for your plots ? Explain.

2. Draw a qualitative sketch of v vs t

3. Answer the question by drawing a qualitative sketch of v vs t if you

threw the fence down instead of dropping it.

Analysis Questions:

1. From the six drops, identify the maximum and minimum from your six

values of the acceleration . DERIVE THE AVERAGE EXPLICITLY by adding up the six numbers and dividing by 6. This work must be shown as if it was a homework problem. Use correct sig. figs. See previous emails and

handouts on how to correctly compute the average with correct sig. figs.

SHOW WORK ! For example from the string of numbers below, identify the

and max are among your six drops. Round the uncertainty to one sig. fig. Round the average to the same decimal place. For example, drawing from the info in emails and handouts, if your uncertainty was

(10.185 - 9.214)/2 = 0.4855, you would round to 0.5. Suppose your average was 9.7870. Then you would report you answer as 9.8 +/- 0.5. As another example, suppose your uncertainty was (9.819 - 9.784)/2 = 0.0175 rounded to 0.02. Then if your average was 9.8018, you'd report 9.80 +/- 0.02. SHOW WORK ! See example in the lab hand out under Analysis Question 4.

5. Find the precision from your data, defined to be

(uncertainty)*100%/average. For example, from the the examples in the

previous questions, the precisions would be (0.4855/9.784)*100 % =

4.9607 % = 5 % and (0.0175/9.8018)*100 % = 0.1785 % = 0.2 % after

rounding to one sig . fig. See example in the lab hand out under

Analysis Question 5.

6. Compare your average with the accepted value 9.80 m/s^2 in two ways;

(i) using the range as discussed in the lab hand out under #5 (ii) using the percent error as suggested by me.